Hydraulic Design of Perforated Breakwaters

Abstract

In the present engineering practice, direct formulas are not given for the preliminary hydraulic design of Jarlan‐type breakwaters: Only qualitative observations and heuristic considerations are reported. The writers analyze the wave attenuation produced by the permeable structure and propose design formulas that can be used for the optimized hydraulic design of Jarlan‐type breakwaters. The proposed model, based on the linear wave theory, is validated by comparison of the theoretical results with the experimental measurements of other authors. The results show that the Jarlan‐type breakwater with a single chamber gives the most effective wave reduction in the range of practical applications and that no particular configuration of the porous wall can be suggested as the best one. The size of the breakwater cannot be standardized, since the optimum hydraulic design of the structure is linked to the parameters of the design wave. Moreover, the proposed design formulas may be used to approximately predict the response of the structure to incident irregular waves.